Stretching device



May21,1946.- R, J TAYL R 2,400,737

STRETCHING DEVICE Filed July 20, 1943 INVENTOR.

Patented May 21, 1946 "This invention :relates" to 'improvements instretching devices and is particularly concerned with. devices whichare; suitable for expanding the handset filamentary material whichareproduced in accordance with my copendingUnited StatesPatentapplications Serial'No'.479,889, ifiled March '20, 1943; SerialNo.'l489',071,ffiled May'29,

1943; and Serial No. 490,009,"-filed"June'8;.1943.

It is an object of this invention to providean apparatus for stretchingor expanding articles having at least two dimensions of substantialmagnitude. It is a further object of this invention to provide a devicein which expansion along at least one dimension is automaticallyaccompanied by a reduction in size along at least one other dimension.It is a further object to provide such a device in which anypredetermined ratio between the expansion along one dimension and thereduction along another dimension may be obtained. Further objects andadvantages will be apparent from the drawing and the description thereofhereinafter.

In the drawing, illustrative of the invention,

Figure 1 is a plan view of one embodiment of the invention,

Figure 2 is an end view thereof,

Figure 3 is an enlarged view of a detail,

Figures 4 and 5 are diagrammatic views illustrating the simultaneousexpansion and contraction of different dimensions by operation of thedevice of Figures 1 to 3,

Figures 6 and '7 are similar diagrammatic views showing the action ofmodification.

In Figures 1 to 3 the device is shown and comprises suitable supportingbeams 2 and 3 carrying transverse rods 4 and 5 which in turn carry theparallel bars 6 and 1 slidable with respect thereto on suitable bearingsleeves B. The bars 6 and I have undercut guideways 9 adapted to receivethe guide-blocks 10 carried by the central pivot pins I I of twoopposite side components of a foursided lazytongs frame. The cross-arms12 of the lazytongs are simply linked for pivotal action, such as bypins or rivets, at their outer points of juncture l3 whereas the pivotsat their inner 45 points of juncture [4 are provided with the materialfastening pins 15. Instead of pins, hooks or clamps may be supplied. Itshould be noted that each side component of the lazytongs frame isjoined to each of the side components adjacent 50 it at two points sothat contraction and expansion of one side is positively transmitted asexpansion or contraction respectively of the adjoining sides. A screw l6having a right-hand thread along half its length and a left-hand thread-along the other half is'supportedonlthe beams 2.and,3, is operablebythehandwheelll and serves tosmove the .bars 6 and 1 together'or apartthrough thecollars l8 and [9 provided with 5 i an appropriate internal.thread -for engaging the screw [6.

Figures 4 and 5 show anillustrativeldimen- 'sional change that may. beobtained. "For ex- ;ample, theilazytongs at the two ends maybe 10collapsed ,asin Figure4rattheinitialstageof op- 15 pins, hooks or clampsat IS, the end lazytongs may be expanded, such as to the position inFigure 5. Such expansion effects a corresponding stretching of thematerial secured thereto and automatically reduces the other sidedimensions.

The ratio of expansion along one dimension to contraction along theother depends upon the extent of expansion of the lazytongs along theends and also upon the initial dimensional relationshi of the frame. Awider range of ratios is obtainable when the cross-arms |2a (Figures 6and 7) along the ends of the lazytongs frame are shorter than thecross-arms l2b. For example, assuming the material to be stretched issecured to the frame as shown in Figure 6, expansion of the frame to theposition of Figure 7 causes an expansion of the width of the materialson the order of about eight to ten times and a contraction in the lengthof only about one-tenth, thus giving a ratio of about eighty to onehundred.

Again, the ratio depends on the extent of expansion of the frame and theinitial dimensional relationship of the frame.

The device constitutes a simple and effective 40 means for expanding thewound bands of my copending applications mentioned above since theexpansion of such bands in width (that is, transversely of the directionin which the filaments extend) is inherently accompanied by a reductionin length. The expansion device may readily be designed for anyparticular band of this character, to effect a predetermined expansionin width and to accompany such expansion with the exact reduction inlength which the band inherently undergoes when thus expanded.

It is to be understood that changes and variations may be made withoutdepartingfrom the spirit and scope of the invention as defined by theappended claims.

I claim:

1. In a device for expanding a material, a framework the sides of whichcomprise lazytongs lever systems, means on the systems for securing thematerial thereto, the system of one side being connected to the systemof each adjacent side by at least two separate pivotal connectionswhereby change in length of one side efiects a change in length of theadjacent sides.

2. In a device for expanding a material, a framework the sides of whichcomprise lazytongs levers having two sets of cross-arms, the juncturebetween adjacent sides of the framework comprising two pivotalconnections between different sets of cross-arm in the levers of theadjacent sides, and means on the levers for securing the materialthereto.

3. In a device for expanding a material, a support, a framework carriedby the support having sides of lazytongs levers, means for varying thedistance between two opposite sides, adjacent sides being interconnectedby at least two separate pivotal connections so that variation in lengthof one side efiects on inverse variation in length of the adjacentsides, and means for securing the material at its edges to the levers.

tongs framework, each lazytongs comprising two sets of pivotally joinedcross-arms, slide means associated with the cross-arms of two oppositesides extending into cooperative engagement with the guideways, thejuncture between adjacent sides of the framework comprising two pivotalconnections between different sets of cross-arms in the lazytongs of theadjacent sides, and means on the lazytongs for securing the materialthereto at its edges.

5. .In a device for varying the dimensions of a material, a frameworkhaving four expansible and contractible side components, means carriedby each side component uniformly spaced therealong for securing thematerial to the 'side components of the framework, two generallyparallel; rigid members having longitudinalguideways, guiding mean ontwo opposite side components engaging the guideways, means for varyingthe distance between said rigid members to cause variation in thedistance between said two opposite side components, each side componenthaving at each end thereof two pivotally

